A hydrothermal route to water-stable luminescent carbon dots as nanosensors for pH and temperature

Abstract

A hydrothermal route to water-stable luminescent carbon dots as nanosensors for pH and temperature, Carbon (2014), doi: http:// dx. AbstractCarbon dots (CDs) as a class of heavy-metal-free fluorescent nanomaterials has drawn increasing attention in recent years due to their high optical absorptivity, chemical stability, biocompatibility, and low toxicity. Herein, we report a facile method to prepare stable CDs by hydrothermal treatment of glucose (glc) in the presence of glutathione (GSH). With this approach, the formation and the surface passivation of CDs are carried out simultaneously, resulting in intrinsic fluorescence emission. The influence of reaction temperature, reaction time and feed ratio of GSH/glc on the photoluminescence property of CDs is studied. The as-prepared CDs are characterized by UV-Vis, photoluminescence, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy and transmission electron microscope, from which their structural information and property are interpreted. Owning to their pronounced temperature dependence of the steady-state fluorescence emission spectra and pH-responsive behavior, resultant CDs could work as versatile nanothermometry devices by taking advantage of the temperature sensitivity of their emission intensity, which change considerably over the physiological temperature range (1560 ºC), as well as a sensor for pH.

Characterization and Analytical Separation of Fluorescent Carbon Nanodots

“…Both SEM and TEM are useful electron microscopy techniques that provide information about the particle size, size distribution, and morphology of C-dots [83,84,[119][120][121][122]. The SEM and TEM images can also be used to investigate whether the agglomeration of particles is present or whether the good [83], (B) TEM [84], and (C) HRTEM [84] image of a bulk sample of C-dots.…”

“…For the characterization of Cdots, XPS has generally been used for the assessment of the elemental composition and the chemical bonds of C-dots in combination with IR. Doping of C-dots with nonmetallic heteroatoms such as N [43,49,56,99,114,121,122,134], S [14,24,46,49,87], Si [50,127,140,141], P [39,49,93], and B [114,142] has been characterized by XPS. A typical example of XPS analysis employed to estimate the surface states and chemical composition of nitrogen and sulfur-codoped C-dots (SNCNs) was displayed in Figure 6 [46].…”

Synthesis of cellulose-derived carbon dots using acidic ionic liquid as a catalyst and its application for detection of Hg2+

“…Thus they have shown great potential in bioimaging [3][4][5], photocatalysis [6], electrocatalysis [7], and chemical sensing [8][9][10][11]. In 2004, CDs were first discovered accidentally during the separation and purification of single-walled carbon nanotubes [12].…”

The visible light catalytic properties of carbon quantum dots/ZnO nanoflowers composites

“…Carbon is environmentally friendly and hardly considered as an intrinsically toxic element, so the carbon materials have become the current focus in research, such as carbon nanotubes, carbon nanowires, grapheme films [1][2][3], especially carbon dots [4,5]. With its high aqueous solubility and biocompatibility, low toxicity and cost, particularly unique up-converted photoluminescence (PL) behavior and photo-induced electron transfer property, carbon quantum dots (C QDs) can act as a potential component in design of semiconductor photoelectric material.…”